Raspberry and Strawberry Shrub

On four quarts of berries pour white vinegar enough to barely cover them. Let them stand for forty-eight hours, then drain off the vinegar, squeezing the juice out of all the fruit with the vinegar. If strawberries are used,
the vinegar must be poured over a second supply of fruit before it will attain the proper flavour; but one supply of raspberries is sufficient. Measure out the liquor when it is ready, and to every pint allow a pound of sugar. Put it in a porcelain-lined kettle with the sugar and let it boil for ten minutes, then bottle it and set away in a cool place. A cupful of this syrup is sufficient to flavour a quart of ice water."